Tape recorders



June 12, 1962 F. c. STOVOLD ETAL 3,038,343

TAPE RECORDERS Filed Nov. 25, 1960 3 Sheets-Sheet 1 Invenlorg Fit-MinxQ. S'fm/nLA A Home y TAPE RECORDERS 3 Sheets-Sheet 2 Filed Nov. 25, l960Inventors y 2 m TR s M W m? v w imam FW @M/ United States Patent C) TAPERECDRDERS Frederick C. Stovold and Wilfred P. Leadley, both of HemelHempstead, and Robert C. Wilson, Luton, England, assignors to Dominus(England) Limited, London,

England 7 Filed Nov. 25, 1960, ar. No. 71,805 Claims priority,application Great Britain Dec. 11, 1959 6 Claims. (Cl. 742ll9) Thisinvention relates to tape recorders and is particu larly concerned withreversing means for tape spools driven by a single reversible motor, atthe high speeds required for Re-winding in one direction and FastForward in the other direction.

It is known to drive the respective spool drums by intermediate frictionpulleys, each of which is driven by a single pulley driven by the onereversible motor, and to move a common support on which the twointermediate pulleys are mounted in one direction or the other about theaxis of the driving pulley so that when one intermediate pulley makesdriving contact with its spool drum the other is out of driving contactwith the other spool drum, the motor being reversed during the operationof moving the support from one driving position to the other. It hasbeen found that the effective driving action of the intermediatefriction pulleys is of relatively short duration (perhaps a matter of afew hours only) when they are mounted on a common support, possiblybecause of the tendency for a driven spool drum to urge its particularpulley out of driving engagement, and possibly because of difiiculty inmaking appropriate contact of each pulley with both the motor pulley (ofsmall diameter) and the spool drum (of substantially greater diameter)for the necessary avoidance of slip at the two points of contact.Avoidance of slip is particularly important if the tape recorder is usedsynchronously with a film projector, tag. a projector driven by the samesingle motor as used for the tape recorder, and the usefulness of theequipment is seriously impaired if faulty reversing means necessitateadjustment every few hours.

The object of the invention is to provide a tape recorder with reversingmeans by which effective drive is transmitted to either of the spoolsrequired to be driven, and can be transmitted over very many hourswithout the need for adjustment or replacement of the elements of thereversing means.

According to the present invention, a tape recorder of the type having asingle reversible motor for driving the tape spool drums selectively inthe Re-wind and Fast Forward directions from a single friction pulleydriven by the motor and rotatable about an axis parallel to and betweenthe axes of the two spool drums, is provided with two intermediatefriction pulleys mounted on axes parallel to those of the single pulleyand the drums but on independent lever supports, each intermediatepulley having a diameter greater than the distance between the singlepulley and one of the drums and its lever support having limited slidingfreedom at its pivot sufficient to permit the intermediate pulley bycombined sliding and rocking of the support to make contact with thesingle pulley and the drum, with a tension spring acting on the supportin its general lengthwise direction to urge the intermediate pulleytowards both such contact positions, together with a V-notched memberslidable transversely with respect to the support between a position inwhich a projection on the support on the side of the support pivotremote from the intermediate pulley pivot descends into the notch underthe urge of a spring, and a position in which the projection is forcedout of the notch against the urge of the spring, one side of the notchin the first of these positions so engaging the projection as to urgethe support and the intermediate pulley towards the drum, and to carrythe spring out of line with the support, while still urging theintermediate pulley towards the drum, the outof-line spring then servingto urge the intermediate pulley away from the drum in the second ofthese positions.

A single slidable member is preferably used to control both supports,the member having two appropriately located V-notches such that when oneprojection can descend into its notch, the other projection is held outof its notch. The spacing of the notches is preferably such that bothprojections can be held out of their notches to provide that neitherintermediate pulley transmits any drive in an interval while the motoris brought to rest and reversed.

Advantageously, when contact is broken between an intermediate pulleyand its drum, contact is also broken with the single pulley.

The invention will now be further described with reference to theaccompanying drawings, as applied to equipment with the axes of themotor, pulleys, and drums horizontal, the single motor serving also fordriving a synchronised film projector, as well as for driving the tapefor Record and Play.

In the drawings- FIGURE 1 is a front elevation of the spool driving andcontrolling mechanism in stop position.

FIGURES 2 and 3 are similar views (with some parts shown in FIGURE 1 nowomitted) of the mechanism in Re-wind and Fast Forward positionsrespectively;

FIGURE 4 is a diagram showing in perspective the driving connectionsbetween the single motor and the reversing means for Re-wind and FastForward, the tape drive for Record and Play, and the film drive; and

FIGURE 5 is a diagrammatic end elevation of a combined tape recorder andfilm projector provided with the single motor drive.

In FIGURE 1, a horizontal motor shaft 1 lies symmetrically between andat the same level as spool drum shafts 2A, 2B parallel to it. The shaft1 carries a small pulley 3 to make driving contact with either of twointer mediate pulleys 4A, 4B having tyres 5 suitable for friction driveby the pulley 3. In the Stop position shown in FIGURE 1, the pulley 3 isout of driving contact with both of pulleys 4A, 4B, 2. condition alsofound in the Play position of the mechanism, to be explained later.

The pulleys 4A, 4B are rotatable about horizontal axes at 6A, 6B onlever supports 7A, 78 respectively depend ing from pivots at 8A, 3B, andeach connected at its bottom end to a tension spring 9A or 9B anchoredat WA or 1013 at a position vertically below the pivot EA or 8B. Thetendency of each spring 9A, 9B is to bring the corresponding pivot 6A,6B into the direct line between 8A, 10A and 83, 10B respectively. Insuch in-line position, thep ulleys 4A, 4B are out of driving contactwith the peripheries of spool drums HA, 1113 on the shafts 2A,

The support levers 7A, 7B extend a little above their pivots 8A, 8B andthere each carries a projecting roller 12A, or 12B rotatable about ahorizontal axis. These rollers are engaged by a slightly inclined slider13 with slots 14 to permit movement in the direction of its length withrespect to support pins 15 engaging the slots. The upper edge of theslider 13 has V-notches 16A, IldB spaced closer together than are therollers 12A, 128, so that in the Stop position shown each roller restson the edge of the slider to the left and right respectively of thenotches. The pivots SA, 813 of the lever supports 7A, 7B are now raisedin vertical guide slots 17A, 17B, so that the springs 9A, 9B are putunder extra tension, ready to urge either of the rollers 12A, 1213 intoa notch 16A, 16B when movement of the slider 13 permits. The raising ofthe supports 7A, 7B is sufficient to bring the pulleys 4A, 4B clear ofthe pulley 3.

The slider 13 is controlled by a crank-operated slider rod 18, the lowerend of which has a lengthwise slot 19 engaged by a support pin 20 andthe upper end of which is pivoted at 21 to a camdisc 22 rotatable abouta horizontal axis 23 by a knob (not shown) to four angular positions I,II, III, and IV representing Re-wind, Stop, Play, and Fast Forwardrespectively. The radius of operation of the pivot 21 about the axis 23provides for crank actuation of the slider rod 18 to move the lattersubstantially in the direction of its own length, with but slightrocking about the pin 20. The slider 13 is urged to the left by atension spring 24 anchored at 25 and this causes a follower roller 26 onthe slider to bear on the right-hand edge of the slider rod 18 over alength forming a 3-step cam. The top 27 of the first step is a slightprojection to the right and corresponds to the Fast Forward controlposition; the intermediate step 28 is a depression, of an extent in thelengthwise direction of the slider rod 18 sufficient to serve both thePlay position and the Stop position; and the bottom 29 of the third stepis a still deeper depression to correspond to the Re-wind position.

In FIGURE 1, the follower roller 26 on the slider 13 bears on theintermediate step 28 of the cam, so that the slider is in the positionfor both rollers 12A, 123 to be held out of the notches 16A, 16B.Rotation of the cam disc 22 from the Stop position shown to the Playposition still leaves the roller 26 on the step 28, so that no movementof the slider 13 results.

The cam disc 22 has two notches 30X, 31W into which is urged a followroller 31 on a brake lever 32A pivoted at 33 and urged by a tensionspring 34- anchored at 35. The lever 32A carries a brake pad 36A to bearagainst the periphery of the spool drum 11A. The lever 32A is connectedby a link 37 to the short upper arm 38 of a second brake lever 32Bpivoted at '39 and carrying a brake pad 36B to bear against theperiphery of the spool drum 1113. In the Stop position shown, thefollower roller 31 lies in the notch 30X, so that the spring 34 bringsboth brake pads 36A, 3613 into braking position. However, when the camdisc 22 is rotated counter-clockwise to Play position the roller 31leaves the notch 36X and the notch 3tlY does not quite reach the roller,so that the brake pads are held out of action. 7

Further counter-clockwise rotation of the cam disc 22 brings the notch31W to the roller 31, which momentarily applies the brake pads in aPause position, before the Fast Forward position in which the roller 31remains on the periphery of the cam disc 22 and maintains the brake padsout of action. At the same time, the rotation of the cam disc 22 has sofar moved the slider rod 18 that the step top 27 has engaged thefollower roller 26 on the slider 13, to push the slider to the right(FIG- URE 3), with a result to be explained below.

Rotation of the cam disc 22 clockwise from the Stop position of FIGURE 1brings the notch 30X clear of the follower roller 31 (FIGURE 2) andbrings the deeper depression 29 of the slider rod 18 into engagementwith the follower roller 26 on the slide 13, so that the spring 24 movesthe slider to the left (FIGURE 2), with a result to be explained below.

The cam disc 22 has a further notch 4-0 for the operation of a pressurebar in the form of a lever 41 pivoted at $2 and carrying at one end afollower roller 43 that lies on the periphery of the disc 22 except inthe Play position, when entry of the roller 43 into the notch 41) allowsthe other end 44 of the bar 41 to depress, to lift the tape pressure padassembly (see FIGURE 4) from the recording heads in the usual way.

FIGURE 2 shows the position of the slider 13 in the Re-wind position ofthe cam disc 22, which has lifted the slider rod 18 to its uppermostposition to allow the spring 24 to draw the follower roller 26 into thedeepdepression 29. The resultant movement of the slider 13 to the leftallows the roller 12A on the lever support 7A to enter the notch 16A, sothat the spring 9A draws the 4 support 7A down, the freedom of thesupport to rock about its pivot 8A in the slot 17A enabling the pulley4A to come into equalised driving contact with.both the motor pulley 3and the left-hand spool drum 11A.

The spring 9A is now out of the direct line between the pivot 8A and theanchorage. The pulley 3 and the drum 11A rotate anti-clockwise forre-winding. Any tendency for the drum 11A to move the pulley 4A out ofcontact with itself is counteracted by the reaction of one side 45A ofthe notch 16A on the roller 12A, which produces a servo effect in thelever support 7A to maintain good driving contact and to minimise slip.

The roller 12B of the lever support remains on the edge of the slider13, so that the lever support 7B, intermediate pulley 4B, and spring 9Bremain as in FIGURE '1, with the pulley 4B clear of both the motorpulley 3 and the right-hand drum 11B.

FIGURE 2 shows the follower roller 31 of the brake lever 32A clear ofthe notch 30X of the cam disc 22, so that the brake pads 36A, 36B(FIGURE 1) are out of action during Re-wind.

Upon a return of the slider 13 from the Re-wind position of FIGURE 2 tothe Stop position of FIGURE 1, the lifting of the lever support 7A bythe forcing of the roller 12A from the notch 16A is accompanied by anurge of the bottom of the support 7A to the right as the spring 9A comesinto in-line position, so that not only is the pulley 4A lifted, but itis also urged to the right to assist in clearing the left-hand drum 11A.

In the Fast Forward position shown in FIGURE 3, the cam disc 22 hasbrought the slider rod 18 toits lowest position, for the engagement ofthe cam step 27 on the follower roller 26 to push the slider 13 to theright. This leaves the lever support 7A unaffected, its roller 12Aremaining on the edge of the slider, but the roller 12B of the leversupport 78 drops into the notch 163, for the spring 9B to draw thesupport 73 down and to rock it about its pivot 8B in the slot 17B, sothat the intermediate pulley 4B comes into equalised driving contactwith the motor pulley 3 and the right-hand drum 11B. The two latterrotate clockwise in this position, and any tendency for the drum 11B tourge the intermediate pulley tB away from itself is countered by theservo effect of the lever support 7B under the reaction of the side 4513of the notch 1613 on the roller 1213.

Upon a return of the slider 13 to the Stop position of FIGURE 1, theout-o-f-line position of the spring 9B with respect to the direct linebetween its anchorage 10B and the pivot 8A causes the intermediatepulley 413 to be urged to the left as it is lifted to ensure that it isclear of the drum 11B.

In FIGURE 1, a crank 46 is rotatable by a control knob (not shown)between two positions V and VI representing Record and Playrespectively. The crank 46 operates a rod 47, guided at 48, so that thefree end 49 of the rod is urged towards the periphery of the cam disc 22in the Record position, but the crank can only be moved to Recordposition if the cam disc 22 has been rotated to a position in which anarcuate notch 50 in its periphery is opposite the end 49 of the rod 47.This ensures (a) that with the cam disc 22 in either the Fast Forwardposition of the Re-Wind position it is impossible tomove the crank 46 toRecor position, and (b) that with the crank 46 in Record position, it isimpossible to move the cam disc 22 to either the Fast Forward positionor the Re-wind position. In this way, the possibility of accidentallyerasing a prerecorded tape is eliminated.

In FIGURE 4 is shown the single reversible motor 51, on the shaft 1 ofwhich is carried the pulley 3 for driving one or the other of theintermediate pulleys 4A, 4B in opposite directions. Between the pulley 3and the motor 51, the shaft 1 carries two pulleys 52, S3 of differentdiameters for selective engagement by an intermediate pulley 54 thatmakes frictional contact with a flywheel pulley 55 that drives a capstanpulley 56 for the tape 57, the tape being held to the capstan pulley bya pressure wheel 53. Near the capstan pulley 56 are the recording anderasing heads 59 below a pressure pad assembly 60. This is the assemblycontrolled by the pressure bar 41 shown in FIGURE 1. The Z-stepdrive ofthe pulley 54 by the pulleys S2, 53 enables the tape 57 to be moved overthe heads 59 at two different speeds.

At the other end of the motor 51 is a pulley 61 for frictional drive ofan intermediate pulley 62, which in turn drives a pulley 63. From thepulley as a shaft 64 is driven through reduction gears 65. The shaft64'. carries a film sprocket 66 and a guide roller 67 for the film 63and also a sprocket 69 for a chain 7d. The film 68 drawn from one spool(not shown) passes from the sprocket 66 and the roller 67 to theprojector (not shown) driven by the chain 7b, as also are a further filmsprocket and guide roller (not shown) leading the film to a takeup spool(not shown).

In FIGURE 5, the motor 51 is shown located in a central compartment 71of a portable combined tape recorder and film projector provided with abase '72 wider than the compartment 71, with removable covers 73, '74provided to enclose the operative parts of the recorder and projectorrespectively. The operation of the motor is controlled by the controlknobs for the cam disc 22 and the crank 46 by appropriate switches, asalso are controlled the recording circuit, the projector lamp, andassociated electrical devices, as for providing synchronous driving ofthe recorder and the projector and independent driving of either ofthese.

What we claim is:

1. A tape recorder having a single reversible motor for driving its twotape spool drums selectively from a single friction pulley reversiblydriven by the motor and rotatable about an axis parallel to and betweenthe axes of the drums, comprising two intermediate friction pulleys withaxes parallel to the drum axes, an independent lever support for theaxis of each intermediate pulley, with provision for sliding at thelever pivot, a spring acting on each lever support and generally in linewith such support to urge the lever support to slide in a direction tobring the intermediate pulley into contact with both a spool drum andthe single friction pulley, aided by the ability of the lever support torock about its pivot, a projection from each lever support at the sideof the pivot remote from the intermediate pulley axis, and a controlmember transversely movable with respect to the projection andcontaining a V-notch to be brought by movement of the member into andout of register with the projection, which member permits the spring toslide the lever when the projection enters the notch, and overcomes thespring when it forces the projection out of the notch.

2. A tape recorder as in claim 1, wherein a single transversely movablemember has the V-notches for the projections of both lever supports, thenotches being so spaced such that when one projection is in its l-notch,the other projection is withdrawn from its V-notch, and also that bothprojections can be simultaneously withdrawn from the notches.

3. A tape recorder as in claim 1, wherein the V- notched member ismovable to a position to receive the projection in the notch in whichone side of the notch provides a fulcrum to resist movement of the leversupport about its pivot in a direction away from that in which theintermediate pulley is urged by the spring towards the tape spool.

4. A tape recorder of the type having a single reversible motor fordriving two tape spool drums selectively in the Re-wind and Fast Forwarddirections from a single friction pulley driven by the motor androtatable about an axis parallel to and between the axes of the twospool drums, provided with two intermediate friction pulleys mounted onaxes parallel to those of the single pulley and the drums, comprisingindependent lever support for each intermediate pulley, each leversupport having limited sliding freedom at its pivot sufiicient to permitthe intermediate pulley by combined sliding and rocking of the supportto make contact with the single pulley and one of the drums, with atension spring acting on the support in its general lengthwise directionto urge the intermediate pulley towards both such con tact positions, aprojection on the support on the side of the support pivot remote fromthe intermediate pulley pivot, together with a control member slidabletransversely with respect to the support and containing a V-notch to bebrought by movement of the member alternatively into a position in whichthe projection descends into the notch under the urge of the spring, anda position in which the projection is forced out or" the notch againstthe urge of the spring, one side of the notch in the first of thesepositions so engaging the projection as to urge the support and theintermediate pulley towards the drum, and to carry the spring out ofline with the support, while still urging the intermediate pulleytowards the drum, the out-of-line spring then serving to urge theintermediate pulley away from the drum in the second of these positions.

5. A tape recorder of the type having a single reversible motor fordriving two tape spool drums selectively in the Rewind and Fast Forwarddirections from a single friction pulley driven by the motor androtatable about an axis parallel to and between the axes of the twospool drums, provided with two intermediate friction pulleys mounted onaxes parallel to those of the single pulley and the drums, comprising anindependent lever support for each intermediate pulley, each leversupport having limited sliding ireedom at its pivot sufficient to permitthe intermediate pulley to make contact with the single pulley and oneof the drums by combined sliding and rocking of the support, a tensionspring acting on the support in its general lengthwise direction to urgethe intermediate pulley towards both said pulley and one of said drums,a projection on the support on the side of the support pivot remote fromthe intermediate pulley pivot, and a control member slidabletransversely with respect to the support and containing two V-notchesselectively to be brought by movement of the member into a position inwhich a projection on one only of the supports descends into that notchunder the force of the spring acting on the support, and a position inwhich the projection is forced out of the notch against the force of thespring, one side of the notch in the first of these positions soengaging the projection as to move the support and the intermediatepulley towards the drum, and to carry the spring out of line with thesupport, while still forcing the intermediate pulley towards the drum,the out-of-line spring then serving to urge the intermediate pulley awayfrom the drum in the second of these positions, the notches being solocated along the control member that when one projection can descendinto one V-notch the other projection is held out of the other V-notchand that both projections can also be held simultaneously out of theV-no-tches.

6. A tape-recorder as in claim 5, comprising a slide rod operativelyconnected to said control member, and a three-step cam coupled to saidrod for bringing the control member to any of three positions in whicheither one or the other projection is in its notch, or neitherprojection is in a notch.

References Cited in the file of this patent UNITED STATES PATENTS431,636 Whitman July 8, 1890 2,711,104 Shields June 21, 1955 2,935,879Morrison et al May 10, 1960

